S
M
T
W
T
F
S
30
77°
55°
31
73°
57°
1
75°
62°
2
78°
59°
3
80°
58°
4
75°
59°
5
79°
54°
6
79°
56°
7
88°
54°
8
92°
59°
9
97°
68°
10
96°
64°
11
81°
61°
12
79°
60°
13
75°
59°
14
85°
55°
15
79°
55°
16
74°
58°
17
75°
61°
18
77°
58°
19
80°
59°
20
74°
59°
21
77°
58°
22
79°
57°
23
86°
61°
24
89°
60°
25
84°
59°
26
78°
56°
27
81°
58°
28
80°
59°
29
81°
57°
30
79°
57°
1
81°
58°
2
74°
52°
3
81°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Jose
San Jose's September 2026 forecast shows daily high temperatures ranging from 74° to 89°, with overnight lows between 52° and 61°. The average high for September is 80° with an average low of 58°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in San Jose. See also: October | November | December.
